CN102322247A - Device and method for evaluating displacement capability of wetting phase of rock at high temperature under high pressure - Google Patents

Abstract

The invention relates to a device and a method for evaluating the displacement capability of a wetting phase of a rock at high temperature under high pressure. The device mainly consists of a displacing device, a thermostat and a pressure pump. The displacing device is positioned in the thermostat and consists of a core chamber, a cone channel and a measurement part. The core chamber is a steel cylinder. A core is placed in the steel cylinder. The bottom of the core chamber is provided with a liquid inlet with a valve. The liquid inlet is connected with the pressure pump outside the thermostat. The measurement part consists of a thick wall glass tube with scales and a steel bushing which is positioned outside the glass tube and is provided with a hole. The core chamber is connected with the measurement part through the cone channel. The device has reliable principle, is simple and convenient to operate and has strong practicality. Not only can the real underground high-temperature and high-pressure oil accumulation environment be simulated, but also the effects of ensuring oil to be rapidly separated from the surface of the core and accurately reading out the oil output are realized, an effectively evaluation approach is provided for the displacement efficiency of the wetting phase in the environment of high temperature and high pressure, and the reliable basis is provided for guiding the site to design a reasonable injection-production scheme.

Description

A kind of device and method of estimating rock wetting phase displacement ability under the HTHP

Technical field

The present invention relates to a kind of petroleum industry field, experimental facilities and the method in oilfield exploitation procedure, the non-wetting phase ability of rock core wetting phase displacement under the high temperature and high pressure environment estimated.

Background technology

The non-wetting phase of wetting phase displacement has been described the transport phenomenon between crack and matrix; Wetting phase is as a kind of displacement power; It is the main mechanism of oil displacement in the waterflooding extraction process; The displacement ability of wetting phase is determining crude oil yield in the fine and close fractured reservoir of hyposmosis (water is wetting phase, and oil is non-wetting phase) exploitation.And in the actual water flooding process, have no idea to know that water injection rate what in the end and waterflood injection rate can realize oil-gas mining the most efficiently.Therefore, the laboratory experiment of assay wetting phase displacement ability is for instructing mining site waterflooding program reasonable in design and raising ultimate recovery to have great importance.

Industry is interior main through under the normal temperature and pressure at present, and the rock core of the oil of satisfying is inserted the device that injection water is housed, and calculates displacement efficiency through the oil mass that the monitoring water drive is replaced, and there is obvious defects in this experimental technique:

(1) the existing experimental technique of estimating wetting phase displacement ability is primarily aimed at the normal temperature and pressure environment, does not have the influence to the wetting phase displacement efficiency of account temperature and pressure effect, promptly can not the true reservoir media of simulate formation.

(2) existing experimental facilities is in order to satisfy visual requirement, and device materials all adopts glass, but glass material can not bear excessive pressure.

(3) the traditional experiment time oversize because the oil of separating out is difficult to break away from attached to core surface, can only realize de-oiling through shaking device, this must cause experimental error.

Summary of the invention

The object of the present invention is to provide a kind of device of estimating rock wetting phase displacement ability under the HTHP; This device can the simulate formation HTHP true reservoir media; Can let oil break away from core surface fast again; Guarantee experimental data accurately and reliably, for rock wetting phase displacement ability under the high-temperature and high-pressure conditions provides the effectively evaluating means.

Another object of the present invention is to provide the method for utilizing this device to estimate rock wetting phase displacement ability under the HTHP, this method principle is reliable, easy and simple to handle, practical, and wide market application prospect is arranged.

For reaching above technical purpose, the present invention provides following technical scheme.

A kind of device of estimating rock wetting phase displacement ability under the HTHP; Mainly form by driving device, insulating box and compression pump; Said driving device is positioned at insulating box; This driving device is made up of three parts: following is measurement section for placing the core chamber of rock core above, and the centre is a tapered channel.Core chamber is the steel cylinder of being processed by stainless steel, and said rock core places in the steel cylinder, and the space between rock core and the steel cylinder is used for the crack of simulated formation with respect to matrix; The inlet of a band valve is arranged at the core chamber bottom; This inlet is connected with the outer compression pump of insulating box; Realize pressurization through the water filling in the above-mentioned simulation fracture of external pressure pump, finish the back in experiment and carry out release that release has given core chamber a pressure ignition process through this compression pump; Oil attached to core surface under this effect can break away from core surface fast, gets into measurement section through tapered channel; Measurement section is made up of the heavy wall glass tube of a band scale, and heavy wall glass tube outside has steel bushing to support, and this steel bushing is with holes, can fix, reinforce glass tube on the one hand, improves the glass tube bearing capacity, and the visualization window of the value of reading is provided on the other hand; In the centre of core chamber and measurement section is a steel tapered channel, and its effect is that the oil that lets displacement go out can get into measurement section quickly and easily on the one hand, realizes two-part connection up and down on the other hand and is convenient to the dismounting of whole device.Compression pump has pressure meter and can monitor in real time core chamber's internal pressure in the whole experiment.Insulating box can be realized temperature control, connects driving device and the compression pump that is positioned at insulating box through pipeline.

The displacement ability of wetting phase receives influence of various factors; Study the weight of these influence factors; At first want under the ground environment of HTHP, to experimentize research; Device provided by the invention can be realized the simulation of true reservoir media, can also monitoring pressure and temperature effect to the influence of wetting phase displacement ability.Experiment will be carried out preliminary treatment such as the desalinization of soil by flooding or leaching, washing oil, oven dry with rock core earlier before experiment; It is oily that pretreated rock core is satisfied; Behind the full oil rock core is put into said driving device core chamber center; Driving device is put in realizes temperature control in the insulating box, utilize compression pump water filling in the core chamber, realize that pressurization and pressure controls.Because the dynamic action water of wetting phase goes out the inner oil of rock core with displacement; After oil is displaced entering " crack "; Because water and oily density contrast; Oil in the glass tube of driving device measurement section, is realized reading of oil pump capacity with floating upward quickly under the pressure ignition process effect of action of gravity and release generation.Pressure size and pressing period can be adjusted through the external pressure pump, experimental temperature can be adjusted through insulating box.Write down the oil volume that goes out under the different conditions, can calculate the displacement oil recovery efficiency by formula (1) (2):

$\mathrm{\η}=\frac{V_2}{V_1}---\left(1\right)$

$V_1=\frac{M_2-{\mathrm{<figure-callout\; id="1"\; label="M"\; filenames="HDA0000069140360000011.png"\; state="\{\{state\}\}">M</figure-callout>}}_1}{\mathrm{\&rho;}}---\left(2\right)$

η-recovery ratio (%)

M ₁, M ₂Quality (g) before and after the full oil of-rock core

V ₁, V ₂Full fully oil volume of-rock core and rock core go out oil volume (cm ³)

ρ-experiment is with the density (g/cm of oil ³)

M in the formula ₁, M ₂Weigh by the precise electronic balance and to obtain V ₁Be indirect amount through calculating, V ₂Obtain through the driving device reading, ρ is a constant.

Under the support of above-mentioned experimental facilities and method, can realize wetting phase displacement ability assessment under the high-temperature and high-pressure conditions.

A kind of method of estimating rock wetting phase displacement ability under the HTHP may further comprise the steps successively:

(1), and, obtains M with weighing before and after the full oil of rock core with the rock core oil of satisfying ₁, M ₂, utilize computes to go out V ₁:

$V_1=\frac{M_2-{\mathrm{<figure-callout\; id="1"\; label="M"\; filenames="HDA0000069140360000011.png"\; state="\{\{state\}\}">M</figure-callout>}}_1}{\mathrm{\&rho;}};$

(2) rock core that will satisfy behind the oil is put into the center of driving device core chamber, and driving device is put in the insulating box, is adjusted to temperature requiredly, will inject water simultaneously and inject core chamber through compression pump, makes rock core be injected into the water logging bubble fully;

(3) continue water filling and make pressure rise to the required pressure of experimental design, the beginning displacement test;

(4) the band scale heavy wall glass tube through the driving device measurement section reads out oil mass V ₂, utilize the displacement efficiency η of computes wetting phase:

$\mathrm{\&eta;}=\frac{V_2}{{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="HDA0000069140360000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_1};$

(5) finish until displacement repeating step (2), (3), (4), thereby realize wetting phase displacement ability assessment under the different pressures temperature.

When the beginning displacement experiment, at first carry out device and detect, water filling builds the pressure to driving device to utilize compression pump, and it is airtight if pressure decline explanation device does not have to spend a few minutes, and whether inspection leaks, if constant pressure explanation device is good.

In order to let oil break away from core surface fast, smear one deck reverse wetting agent in core chamber and tapered channel inner surface, make the steel cylinder inner surface hydrophilic, the oil of avoiding separating out can not all get into measurement section attached to its surface.

In order further to guarantee experimental data accurately and reliably, also should rock core be carried out preliminary treatment such as the desalinization of soil by flooding or leaching, washing oil, oven dry before the full oil of rock core.

Compared with prior art, measuring method provided by the invention and principle of device are reliable, and be simple in structure, workable, and its beneficial effect is:

(1) the true reservoir media of ability simulate formation HTHP guarantees the true and reliable of experiment condition;

(2) can easily regulate experimental temperature and pressure, monitor temperature and pressure change the influence to wetting phase displacement ability;

The oil of (3) separating out behind the traditional experiment can influence the value of reading of oil pump capacity attached to core surface, and the present invention has realized letting oil break away from core surface fast and can accurately read out oil mass.

Therefore the present invention provides reliable foundation for the displacement efficiency of estimating wetting phase under the true reservoir media of HTHP provides the effectively evaluating means for instructing Site Design to go out rational injection-production program.

Description of drawings

Fig. 1 is the structural representation of traditional displacement measurement mechanism.

Fig. 2 is the structural representation that the present invention estimates the device of rock wetting phase displacement ability under the HTHP.

Fig. 3 is the structural representation of driving device among Fig. 2.

Among the figure: 1 cloche; 2 glass flumes; 3 rock cores; 4 compression pumps; 5 connecting lines; 6 driving devices; 7 insulating boxs; 8 valves; 9 core chamber; 10 inject water; 11 tapered channels; 12 band scale heavy wall glass tubes; 13 steel bushings with holes.

The specific embodiment

Further specify the present invention below in conjunction with accompanying drawing.

See Fig. 1.Fig. 1 is traditional displacement measurement mechanism, in glass flume 2, holds simulation and injects water; Rock core 3 is put into the tank middle position, make rock core be in simulation injection water environment and soaked fully by water; Put cloche 1 into tank rock core is surrounded, begin flood pot test then, the oil of separating out can get into the top of cloche automatically under action of gravity, write down oil pump capacity with this.

See Fig. 2, Fig. 3.

A kind of device of estimating rock wetting phase displacement ability under the HTHP; Mainly form by driving device 6, insulating box 7 and compression pump 4; Said driving device is positioned at temperature control box, and said driving device is made up of core chamber 9, tapered channel 11 and the measurement section of placing rock core 3, and said core chamber is a steel cylinder; Said rock core places in the steel cylinder; Space between rock core and the steel cylinder is used for the simulated formation crack, and the inlet of band valve 8 is arranged at said core chamber bottom, and this inlet is connected through connecting line 5 with the outer compression pump 4 of insulating box; Said measurement section by a band scale heavy wall glass tube 12 with being positioned at glass tube outer steel bushing with holes 13 form, said core chamber 9, measurement section are connected through tapered channel 11.

Before beginning test; Need check at first whether the driving device (see figure 3) is airtight; Carry out the water filling 1MPa that builds the pressure through 8 pairs of core chamber of liquid flowing valve, see after 2 minutes that the constant explanation seal of indicating value of compression pump upward pressure table is good, no longer descend until pressure otherwise then reexamine test; Smear one deck reverse wetting agent in core chamber and tapered channel inner surface, make the steel cylinder inner surface hydrophilic, the oil of avoiding separating out can not all get into measurement section attached to its surface; Use long 50mm diameter to be the oily preliminary treatment of carrying out the desalinization of soil by flooding or leaching, washing oil, dry, weigh and satisfy of the standard rock core of 25mm test; Pretreated rock core is weighed after with clean its surface oil of towel wiping, put seal is intact on inspection driving device core chamber 9 middle positions and device for screwing up after weighing into; The driving device that debugging is good is put into the insulating box that temperature is set to 60 °, and the compression pump 4 through the outside injects simulation in the cavity between rock core and the steel cylinder in the core chamber and injects water 10, makes rock core be fully immersed in injection water; Continuation through the compression pump water filling with pressure rise to the experiment required (1MPa, 2MPa, 3MPa, 5MPa), the beginning displacement test; Pressurize after 5 hours; Utilizing the valve that is connected with core chamber to carry out pressure discharges; Oil is the spontaneous visual part of measurement section that just got in this process, when pressure was reduced to normal pressure relief device static 1 hour, but reads out oil mass through driving device top optic zone scale heavy wall glass tube; Can calculate displacement efficiency with this, realize wetting phase displacement ability assessment.

Claims (2)

1. device of estimating rock wetting phase displacement ability under the HTHP; Mainly form, it is characterized in that said driving device is positioned at temperature control box by driving device (6), insulating box (7) and compression pump (4); Said driving device is made up of core chamber (9), tapered channel (11) and measurement section; Said core chamber is a steel cylinder, and said rock core (3) places in the steel cylinder, and the space between rock core and the steel cylinder is used for the simulated formation crack; The inlet of band valve (8) is arranged at said core chamber bottom; This inlet is connected with the outer compression pump (4) of insulating box, and said measurement section is with scale heavy wall glass tube (12) by one and is positioned at the outer steel bushing with holes (13) of glass tube and forms, and said core chamber (9), measurement section are connected through tapered channel (11).

2. utilize the described device of claim 1 to estimate the method for rock wetting phase displacement ability under the HTHP, may further comprise the steps successively:

(1), and, utilize computes to go out V with weighing before and after the full oil of rock core with the rock core oil of satisfying ₁:

$V_1=\frac{M_2-M_1}{\mathrm{\&rho;}}$

M wherein ₁, M ₂---the quality (g) before and after the full oil of rock core,

ρ---experiment is with the density (g/cm of oil ³);

(2) rock core that will satisfy behind the oil is put into the center of driving device core chamber, and driving device is put in the insulating box, is adjusted to temperature requiredly, will inject water simultaneously and inject core chamber through compression pump, makes rock core be injected into the water logging bubble fully;

(3) continue water filling and make pressure rise to the required pressure of experimental design, the beginning displacement test;

(4) the band scale heavy wall glass tube through the driving device measurement section reads out oil mass V ₂(cm ³), utilize the displacement efficiency η of computes wetting phase:

$\mathrm{\&eta;}=\frac{V_2}{V_1};$

(5) finish until displacement repeating step (2), (3), (4), thereby realize wetting phase displacement ability assessment under the different pressures temperature.

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